Is the Russian-made Sukhoi SU-24 Fencer obsolete?

Early January 2008, the Russian Ministry of Defense reported that the new Sukhoi Su-34 fighter bomber would begin to enter service in the Russian military, replacing legacy Su-24 Fencer in the front-line use.

Although in the mid-80s, Sukhoi began developing a new tactical combat aircraft to replace the swing-wing Su-24, thus Sukhoi selected the Su-27, which had excellent maneuverability and long range, and could even carry a large payload. Hence the resemblance with the Su-27 can be easily observed. The aircraft shares most of its wing structure, tail, and engine nacelles with the Su-27/Su-30, with canards like the Su-30MKI, Su-33, and Su-27M/35 for higher maneuverability.

The aircraft has an entirely new nose and forward fuselage with a unique cockpit design with a side-by-side seating for a crew of two. There is no doubt that the Su-34 is vastly superior to the Su-24 that it is replacing but the question most people (mostly the current Su-24 users) are asking is; How relevant is our own fleet of Fencers in the present (and possibly the future) scheme of things? How effective are the Fencers in the current theat assessment? Are they still worth keeping?
As with other technologies worldwide, if a tech or device has been replaced my a new (or better) device the best practice is to either go the expensive (and safer) way or the cheaper way which is:

To replace the tech/device with the newer one (expensive)

To upgrade the current tech/device features or replace the components with newer ones.

This questions would have been valid when looking at other less advance technologies but with higher and more advanced technologies like airplanes, it makes more sense to keep your Su-24 Fencers and upgrade them with new software, Radars, Engines e.t.c.

Su-24 bomber design
The Su-24 front-line bomber is manufactured by the Sukhoi Design Bureau Joint Stock Company, based in Moscow, and the Novosibirsk Aircraft Production Association, Novosibirsk, Russia. Over 900 Su-24s have been delivered, and the aircraft is in service with the Russian Air Force and Navy, and the air forces of Azerbaijan, Algeria, Belarus, Kazakhstan, Libya, Syria and Ukraine.

The Su-24 front-line bomber is designed to penetrate hostile territory and destroy ground and surface targets in any weather conditions, by day and night. Variants of the Su-24 have also been produced, designed for reconnaissance and electronic countermeasures.The Su-24 remains a powerful long-range, low-level strike attack aircraft with an all-weather precision attack/strike capability. With its variable geometry swing wing and side-by-side cockpit, the Su-24 is inevitably compared with the US General Dynamics F-111.

The aircraft has a conventional aerodynamic configuration with a variable-sweep shoulder wing. The fuselage is of rectangular-section semi-monocoque design, with a two-seat pressurised cockpit. The wing sweep-back angle varies from 16° to 69°, with respect to the wing leading edge with four outer-wing panel fixed positions of 16°, 35°, 45° and 69°.

Su-24 Fencer spooks US Most powerful Destroyer (USS Donald Cook)
The State Department acknowledged that the crew of the destroyer USS Donald Cook has been gravely demoralized ever since their vessel was flown over in the Black Sea by a Russian Sukhoi-24 (Su-24) fighter jet which carried neither bombs nor missiles but only an electronic warfare device. On 10 April 2014, the USS Donald Cook entered the waters of the Black Sea and on 12 April a Russian Su-24 tactical bomber flew over the vessel triggering an incident that, according to several media reports, completely demoralized its crew, so much so that the Pentagon issued a protest.

Russian Sukhoi Su -24 with the newest jamming complex paralyzed in the Black Sea the most modern American combat management system “Aegis” installed on the destroyer “USS Donald Cook”. Pavel Zolotarev, Deputy Director, Institute of USA and Canada, shares details about this version which is being actively discussed in the Russian media and by bloggers.

Is the Russian-made Sukhoi SU-24 Fencer obsolete?
Reviewed by African Military Blog
on
May 02, 2016
Rating: 5